Synthese von Heterocyclen mit Hydroxymethylenketonen. XIV [1]. Zur Regioselektivität der Reaktion von Acetylacetaldehyd mit Tryptamin

Synthesis of Heterocyclic Compounds with Hydroxymethylene Ketones. XIV. Contribution to the Regioselectivity of the Reaction of Acetoacetaldehyde with Tryptamine The range of substitution products of tryptamine with acetoacetaldehyde as substituent at the basic or the indole nitrogen ( 2, 3 ) is completed by a product containing the substituent in the indole α-position ( 5 ). It is formed by ring opening of the tetrahydro-β-carboline 4 . The reaction conditions are commented and the ¹H-NMR spectra comparatively discussed. The synthesis of the azocino-indole 7 is described.